1. Field of the Invention
This invention relates to an automobile engine idling stop apparatus for stopping engine idling of an automobile when an automobile stops at an intersection or the like, a system thereof and a signal display apparatus used for displaying an indication related to idling stop.
More specifically, this invention relates to an automobile engine idling stop apparatus for automatically stopping the idling of an automobile engine when an automobile temporarily stops at an intersection or the like to wait for a traffic signal lamp to change, a system thereof and a signal display apparatus used in the system, wherein the signal display apparatus is connected to a traffic signal device for stopping the automobile on the road, a railroad crossing gate and the like so as to be operated in association therewith to prompt a driver to stop engine idling.
2. Description of the Related Art
When automobiles wait for a traffic signal to change to red for a predetermined period of time, ordinarily, the drivers wait for the change of the traffic signal while keeping engines in an idling state in most cases. By continuing the engine idling, not only the fuel supplied thereto during the idling time is wastefully consumed but also global warming substances such as carbon dioxide (CO2) and the like and gases such as nitrogen oxide (NOx) and the like which are harmful to human bodies are discharged. To cope with this problem, an xe2x80x9cidling stop campaignxe2x80x9d is being conducted in some districts to promote the idling stop of automobile engines when automobiles are at rest.
Apparatus for controlling the stop of automobile engines have been proposed. The engine stop control apparatus are arranged for temporary stop of the automobile engines when the automobile stops at a red signal or meets a traffic jam. These apparatuses are proposed in the technologies disclosed in, for example, Japanese Unexamined Patent Publication No. 11-62650.
According to the technology disclosed in Japanese Unexamined Patent Publication No. 11-62650, any one of a normal cruising mode or an idling stop/energy saving cruising mode is previously selected by a mode selection switch. In the case that the idling stop/energy saving cruising mode is selected, it is possible to stop an engine at temporary stoppage of an automobile and then to restart the engine, by the ordinary driving operation such as the depression of a brake pedal and the shift operation of a shift lever. By this operation, an idling-stop-controlled automobile can be realized, whereby fuel consumption is saved and atmospheric pollution is prevented in a global scale.
When a driver waits for signal change from red to green or a driver waits for train passing at a lowered gate of a railroad crossing, the driver usually keeps the engine in an idling state without stopping. The reason is to promptly start an automobile just after the red signal is changed to green or gate arm is lifted after train passing. However, gasoline is wastefully consumed by keeping the engine in the idling state during the automobile stoppage.
In addition to the above, the engine discharges global warming substances such as carbon dioxide (CO2) and the like and gases such as nitrogen oxide (NOx) and the like which are harmful to human bodies. Therefore, an xe2x80x9cidling stop campaignxe2x80x9d is being conducted in some districts to promote the idling stop when an automobile is at rest as described above. However, a major reason why the xe2x80x9cidling stop campaignxe2x80x9d does not become widespread resides in the nuisance of stopping an engine.
FIG. 13 shows a discharge characteristics of an amount of nitride oxide (NOx) before and after stopping an engine idling. In the figure, xe2x80x9cixe2x80x9d shows a NOx discharge level in idling state. Numeral t1 denotes a time at which idling is stopped and numeral t2 denotes a time at which an engine is restarted. A slanting-lined region M1 shows an amount of exhaust gas which is reduced by an idling stop. A slanting-lined region M2 shows an excess amount of exhaust gas which is increased by highly concentrated exhaust gas at engine restart, in comparison with the continuous idling.
Thus, no NOx gas is discharged for a period of time t by stopping the idling, and the amount of exhaust gas reaches a peak value which exceeds the level of the idling start by restart of the engine and then it is lowered to the level of the idling state as a time passes. In the case that the region M2 is smaller than the region M1, the idling stop is effective to reduce the exhaust gas. Note that curves showing variations of the exhaust gases, which are similar to that of NOx, are also drawn similarly as to CO2, CO and THC.
However, there are cases in which it is not always preferable to stop idling when an automobile is stopped at a stop signal (red signal) and the like, for example, as shown below.
(1) When an engine is restarted, the amount of fuel required in a cranking process (a process for restarting the engine by rotating a starter motor) is more than the amount of fuel needed in continuous idling. In this case, fuel is much consumed by the idling stop.
(2) When an engine is restarted, harmful exhaust gas are discharged more than that of the exhaust gases discharged in continuous idling. In this case, the harmful exhaust gas are discharged more than that in the idling stop.
(3) A battery load is excessively increased when the head lamps are turned on at night or air conditioning is carried out. In this case, there may be a possibility that the battery goes dead and an engine cannot be restarted.
In the above cases, harmful effects are caused by the stop of idling.
As a reason why xe2x80x9cthe idling stopxe2x80x9d is not widely popularized even though a driver recognizes the effect of it, there is the conventional custom that the driver cannot instantaneously recall the idling stop and misses a timing for the action, in addition to the driver""s bothersome feeling of the idling stop action.
Further, still another reason is that the driver may find it unpleasant to have to promptly run an automobile by restarting the engine idling just before signal changes from red to green or just before a crossing gate is lifted.
To solve the above problems, an object of the invention is to provide an automobile engine idling stop apparatus and a system thereof capable of reducing the wasteful consumption of fuel and the discharge of harmful exhaust gases by stopping idling as well as capable of restarting the engine without giving feelings of anxiety to a driver.
It is another object of the present invention to provide an idling stop signal display apparatus as an apparatus effective to make an xe2x80x9cidling stopxe2x80x9d campaign to become widespread, the apparatus being arranged such that it prompts a driver to stop an engine at a proper timing while a traffic signal device displays a red signal or while the gate arm of a crossing gate is lowered and then notifies the driver of a time at which the engine is to be restarted.
[Means A, to Solve the Theme]
To achieve the above objects, according to a first aspect of the invention, there is provided an automobile engine idling stop apparatus which comprises receiver means for receiving a signal transmitted from a roadside apparatus and indicating a period of time until a traffic signal changes from a present time; detection means for detecting the state of an automobile including the running condition thereof; and control means for controlling idling stop based on the signal received from the receiver means and the state of the automobile detected by the detection means.
According to the first aspect of the invention, the receiver means receives the signal which is transmitted from the roadside apparatus (for example, a traffic controller such as a traffic signal device, a beacon for detecting traffic jam, or the like) and indicates the period of time until the traffic signal changes from the present time (for example, a period of time from a time at which the automobile is stopped by a red traffic signal or a traffic jam to a time at which the automobile is to begin running).
The detection means detects the state of the automobile including the running condition thereof, for example, a running speed of the automobile, operating status of a foot brake and a parking brake at stoppage, running condition of the automobile such as the head lamps direction indicators, and an air conditioner, or the like. The control means controls the idling stop of the automobile engine based on the signal received from the receiver means and the states of the automobile detected by the detection means. Therefore, in the case that a large load is imposed on a battery which is necessary to restart the automobile engine, it is possible to continue the idling without stopping it.
Further, the control means calculates an idling stop period of time based on the received signal and the state of the automobile, and the engine idling is controlled depending upon whether or not an idling stop effect can be obtained from the calculated idling stop period of time. For example, when the calculated idling stop period of time is not sufficient to obtain the idling stop effect, the idling is continued.
Accordingly, the wasteful consumption of fuel and the discharge of harmful exhaust gases can be reduced by stopping the idling and restarting the engine.
In a second aspect of the invention, the frequency of the signal of the first aspect of the invention may be made to a first frequency when the traffic signal of a traffic signal device is changed to a stop signal (red) and made to a second frequency when the stop signal (red) is changed to the go signal (green) and the frequency of the signal may be continuously shifted from the first frequency with passage of time of the stop signal (red) continues.
According to the second aspect of the invention, the receiver means of the first aspect of the invention may receive the signal whose frequency may be made to the first frequency when the traffic signal of the traffic signal device is changed to the stop signal (red) and may be made to the second frequency when the stop signal is changed to the go signal (green) and may be continuously changed (for example, linearly changed) from the first frequency to the second frequency with passage of time of the stop signal (red). By receiving the above signal, a period of time, i.e. from the time at which the stop signal is received to the time at which the stop signal is changed to a go signal (green) can be calculated. Based on the above calculated result, the control means can control the idling state of the automobile engine, that is, to keep the engine idle or to stop/restart engine idling, as to reduce wasteful fuel consumption and harmful exhaust gases.
In a third aspect of the invention, the control means of the first or second aspect of the invention may stop idling in the case that a reduced amount of fuel by the idling stop exceeds an excess amount of fuel which is consumed by the engine restart.
According to the third aspect of the invention, since the control means of the first or second aspect of the invention may stop the idling in the case that the reduced amount of fuel by the idling stop exceeds the excess amount of fuel which is consumed by the engine restart, that is, in the case that the idling stop effect can be obtained, the amount of fuel consumption can be reduced.
And, the engine idling is kept continuously when the excess amount of fuel which is consumed by the engine restart exceeds the reduced amount of fuel by the idling stop. In this case, the excess consumption of fuel can be prevented by the continuous idling of the automobile engine.
In a fourth aspect of the Invention, the control means of any of the first to third aspects of the invention may stop the idling in the case that a reduced amount of harmful exhaust gases by the idling stop exceeds an excess amount of harmful exhaust gases by the engine restart.
According to the fourth aspect of the invention, since the control means in any one of the first to third aspects of the invention may stop the idling in the case that the reduced amount of harmful exhaust gases by the idling stop exceeds the excess amount of harmful exhaust gases by the engine restart, that is, in the case that the idling stop effect can be obtained, the harmful exhaust gases discharged by the idling can be reduced.
And, the idling is continued when the excess amount of harmful exhaust gases by the engine restart exceeds the reduced amount of harmful exhaust gases by the idling stop. In this case, the discharge of the harmful exhaust gases at the engine restart can be prevented by keeping the engine idling without interruption.
In a fifth aspect of the invention, the control means in any one of the first to fourth aspects of the invention may restart the automobile engine before a predetermined period of time when the traffic signal lamp of the traffic signal change to green.
According to the fifth aspect of the invention, since the control means of any one of the first to fourth aspects of the invention may restart the automobile engine before a predetermined period of time when the traffic signal of the traffic device is changed to green. The automobile can be started as soon as the traffic signal of the traffic signal device changes to green. Thus, the engine can be restarted without giving any anxiety to a driver.
In a sixth aspect of the invention, the control means of any of the first to fifth aspects of the invention may continue the idling of the engine when the state of the automobile detected by the detection means is such that electrical components including at least lamps and an air conditioner are in use.
According to the sixth aspect of the invention, the control means of any of the first to fifth aspects of the invention may continue the idling of the engine when the state of the automobile detected by the detection means is such that the electrical components including at least the lamps (for example, head lamps, auxiliary head lamps or the like) and the air conditioner are in use. Thus, when a large load is imposed on the battery which is kept idling continuously in order to prevent burning out the battery capacity and to be able to restart the engine.
In a seventh aspect of the invention, an automobile engine idling stop system includes the automobile engine idling stop apparatus of any one of the first to sixth aspects of the inventions and a transmitter means disposed on the part of a road for transmitting a signal indicating a period of time until a traffic signal changes from a present time to green.
According to the seventh aspect of the invention, the transmitter means disposed on the part of the road (for example, the traffic signal device or the traffic controller such as the beacon or the like for detecting traffic jam) transmits a signal indicating the period of time until the traffic signal changes from the present time to green (for example, the period of time from the time at which the automobile is stopped by the red traffic signal or the traffic jam to the time at which the automobile can be started). Since the signal may be received by the receiver means in the automobile engine idling stop apparatus in any one of the first to sixth aspects of the invention, the idling stop may be controlled or the engine may be restarted based on the signal as described above.
In an eighth aspect of the invention, the transmitter means of the seventh aspect of the invention may be mounted in conjunction with the traffic signal device.
According to the eighth aspect of the invention, since the transmitter means in the seventh aspect of the invention may be mounted in conjunction with the traffic signal device, it may transmit a signal indicating a period of time until the traffic signal lamp of the traffic signal device is changed from a stop signal (red signal) to a go signal (a green signal or an arrow signal). Thus, the control means may control the engine idling depending upon whether or not the idling stop effect can be obtained during the period of time indicated by the transmitted signal. That is, the wasteful consumption of fuel and the discharge of harmful exhaust gases can be reduced by stopping the idling and restarting the engine without any detrimental effects caused by the idling stop as well as the engine can be restarted without giving any anxiety to the driver.
[Means B, to Solve the Theme]
To solve the above problems, there is provided an idling stop signal display apparatus connected to traffic relating equipment for prompting a walker or a traveling automobile to stop comprising display means capable of making a display for prompting an automobile at rest at least to stop an engine and to restart the stopped engine; and control means having a function for determining a time zone during which it is preferable to stop the engine based on the signal input from the traffic relating equipment and causing the display means to make a display for prompting the engine to stop as well as a function for determining a time zone during which it is preferable to restart the stopped engine and causing the display means to make a display for prompting the engine to restart.
Then, the traffic relating equipment may be a traffic signal device installed at an intersection or the like and connected thereto and the control means divides the time zone during which a red signal is turned on for a predetermined period of time at predetermined intervals in a time series direction based on input red signal display information, and has a function for causing the display means to make a display for prompting the engine to stop in the first divided section of a plurality of divided sections and a function for causing the display means to make a display for prompting the engine to restart in the final section of the plurality of divided sections.
Specifically, in the case that the length of an preceding red signal exceeds a predetermined period of time, the control means may control the display means such that the display means sequentially makes a first display for prompting the engine to stop, a second display for prompting the engine to leave as it is which follows the first display and a third display for prompting to restart the engine which follows the second display, whereas when the length of the information of the immediately preceding red signal does not exceed the predetermined period of time, the control means may control the display means such that the display means make only the second display.
Further, the traffic relating equipment may be a crossing gate of a railroad and connected thereto and the control means may cause the display means to make a display for prompting the engine to stop of the automobile based on a signal input to the apparatus which indicates that a train has approached or a crossing arm has been lowered and to make a display for prompting the engine to restart based on an input signal to the apparatus which indicates that the train has passed.